code: def expect_color_at(self, ts, expected, xy=[0, 0]):
      frame = self.clip.make_frame(ts)
      r, g, b = expected
      actual = frame[xy[1]][xy[0]]
      diff = (
          abs(actual[0] - r) + abs(actual[1] - g) + abs(actual[2] - b)
      )
  
      mismatch = diff > ClipPixelTest.ALLOWABLE_COLOR_VARIATION
      assert not mismatch, (
          "Expected (%02x,%02x,%02x) but got (%02x,%02x,%02x) at timestamp %s"
          % (
              *expected,
              *actual,
              ts,
          )
      )
  
file_path: moviepy/tests/test_compositing.py
imports: import os
  import numpy
  import pytest
  from moviepy.video.compositing.CompositeVideoClip import CompositeVideoClip, clips_array
  from moviepy.video.compositing.concatenate import concatenate_videoclips
  from moviepy.video.compositing.transitions import slide_in, slide_out
  from moviepy.video.fx.resize import resize
  from moviepy.video.VideoClip import BitmapClip, ColorClip
label_desc: Use image node_id 2 for calling the ClipPixelTest obj's underlying member method code with example usage: obj.expect_color_at(ts, expected, xy) without return types